Splitting cavity blocks

Angle-grinder with a concrete cutting disk would be my preferred method. Never got the scoring method to work well.

It's a cavity block, right, so you're making what's called a 'football', which is almost a half, except it's not.

https://brooksonline.ie/7-5n-half-cavity-football-215mm-ue2490

So you'd cut or deeply score both sides along this red line and then break and discard the broken half with the X.

A standard cavity block is 440mm wide, while a football is 215mm, so what you're making is roughly 230mm wide - so not square like a true cavity-block-football… if you get my drift. 😁

Is that answering the question?

It will be much weaker and hence easier to break if you dont to it in the centre, if you just drop it on an edge it will probably break right where you want it to because of this, the scoring just helps to guide the break where you want it.

The internal cross member is for strength, so that is probably the strongest part of the block, hence you will make sh1t of it if you try to break it there :)

Scoring works well anywhere on solid bricks/blocks because the scored section is a weak point in an otherwise uniform strength brick/block.